package com.hmdp.service.impl;

import cn.hutool.core.util.StrUtil;
import cn.hutool.json.JSONUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.ShopType;
import com.hmdp.mapper.ShopTypeMapper;
import com.hmdp.service.IShopTypeService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisConstants;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.List;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class ShopTypeServiceImpl extends ServiceImpl<ShopTypeMapper, ShopType> implements IShopTypeService {
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    /**
     * 查询店铺类型list
     *
     * @return
     */
    @Override
    public Result queryShopList() {
        //1.从redis中查询
        String cacheShopTypeListKey = RedisConstants.CACHE_SHOP_TYPE_LIST_KEY;
        String shopTypeListCache = stringRedisTemplate.opsForValue().get(cacheShopTypeListKey);
        //2.存在 直接返回
        if (StrUtil.isNotBlank(shopTypeListCache)){
            List<ShopType> shopTypeList = JSONUtil.toList(shopTypeListCache, ShopType.class);
            return Result.ok(shopTypeList);
        }
        //3.不存在 从数据库中查询
        List<ShopType> shopTypeList = query().orderByAsc("sort").list();
        //4.数据库中不存在 返回错误信息
        if(shopTypeList.isEmpty()){
            return Result.fail("店铺分类信息为空");
        }
        //5.数据中存在 返回信息 并写回redis
        stringRedisTemplate.opsForValue().set(cacheShopTypeListKey,JSONUtil.toJsonStr(shopTypeList));
        return Result.ok(shopTypeList);
    }
}
